During recent years there has been a spectacular growth in the number of mobile telephones. Motor vehicles have become offices on wheels wherein individuals, businessmen and professionals such as, doctors and lawyers, manage their affairs and conduct their business. Moreover, portable mobile telephones have made it possible to conduct business at virtually any place and any time during the day. They have also increased safety by providing continuous communication to link persons equipped with portable telephones.
A serious problem with portable telephones is that incoming calls in motor vehicles are obscured by ambient noises, such as engine, wind, road and traffic noises. The problem is accentuated in hearing impaired persons. One consequence of this problem is that when operating the telephone, a driver's attention is diverted from the road. A contributing cause is that portable telephones are low power devices. Another cause is that portable telephones are provided with small earpieces. The ambient noise problem is expected to increase because of the increase in the number of vehicle and telephones and the desire to increase telephone portability by reducing their size.